Feasibility and Safety of High-Power Settings for Electrical Isolation of the Superior Vena Cava Using a Catheter Capable of Local Impedance and Contact Force Monitoring.

INTRODUCTION

Recently, catheters incorporating both contact force (CF) sensing and local impedance (LI) measurement-an indicator of tissue temperature-have become clinically available. The present study aims to evaluate the efficacy of superior vena cava isolation (SVCI) using this catheter and to investigate the characteristics of impedance during the procedure.

METHODS

This retrospective study included 64 patients undergoing initial SVCI using the StablePoint catheter (40 W, CF 10-20 g, 8-10 s). We analyzed the success rate of SVCI and impedance data collected from 1 402 ablation points, with particular attention to the dynamics of LI and generator impedance (GI).

RESULTS

First-pass isolation was achieved in all cases without complications such as phrenic nerve or sinus node injury. The LI drop was significantly greater and faster than the GI drop in all segments. The 90% decay time of LI was consistently 5-6 s, suggesting effective lesion formation during the resistive heating phase. LI provides a more reliable and localized indicator of tissue response than GI. The temporal profile of LI supports its utility in guiding safe and effective lesion delivery, particularly in the thin myocardial tissue of the SVC.

CONCLUSION

High-power ablation guided by LI and CF using the StablePoint catheter enables safe and effective SVCI with accurate real-time assessment of lesion quality.